Aquarium filtration indicator

ABSTRACT

An aquarium filtering device comprising a housing in which is provided a partition for separating the housing into first and second chambers in communicating relation. The housing is provided with at least one opening through which water may enter into the first chamber from an external water-carrying source. The second chamber includes a filtering assembly for cleansing water which has entered the first chamber and which, thereafter, flows into the second chamber. An air conduit is provided for directing air into the second chamber for drawing water through the filtering assembly. Likewise, a conduit is provided for directing both air and cleansed water out of the second chamber after the water has been cleansed by the filtering assembly. A rotary indicator is provided for signalling visually the rate of inflow of water into the first chamber and outflow from the latter into the second chamber so as to guide adjustment and cleansing of the filtering device.

United States Patent Willinger et al. [4 July 17, 1973 1 AQUARIUMFILTRATION INDICATOR Pr im ai'y Eiammersamih N. Zaharna 75 Inventors:Allan II. Willin er Clifton, N.J.; Atiiflflh m "BE 1 Albert mnnegstin,Far Attorney-Abraham FrIedman and Abraham Good- Rockaway, N.Y.; AvihuKagan, man U919, 57 ABSTRACT Assignee: Metah'ame Corporation, Maywood,An aquarium filtering device comprising a housing in which is provided apartition for separating the housing [22] Filed. Nov. 23, 1971 intofirst and second chambers in communicating relation. The housing isprovided with at least one opening PP 201,502 through which water mayenter into the first chamber from an external water-carrying source. Thesecond 52 us. c1. 210/87, 210/169 Chamber includes filtering assemblyfor cleansing 51 Int. Cl B01d 35/14, E04h 3/20 Water which has enteredthe first chamber and which, [58] Field of Search 210/169 90-98,thereafter, hm the second chamberah 210 103 117 110 104 105 7; 11 1 17 Rduit iS plOVldFd for directing air into the second cham- I ber fordrawing water through the filtermg assembly. 561 References CitedLikewise, a conduit is provided for directing both air UNITED STATESPATENTS and cleansed water out of the second chamber after the water hasbeen cleansed by the filtering assembly. A r0- ;23 10/1933 f? 20/94 taryindicator is provided for signalling visually the rate ggg 2: 1:32; ofinflow of water into the first chamber and outflow 14492l7 3/1923 Davis116/117 from the latter into the second chamber so as to guide 31276158610/1966 kosaeii il:I:..................:::.. 210 91 adjustment andcleahsihg of the filtering device- FOREIGN PATENTS OR APPLICATIONS 12Claims, 4 Drawing Figures 839,5,92 6/1960 Great Britain 116/117III/I/I/I/g Patented July 17, 1973 3 Sheets-Sheet 1 FIG. I'.

Patented July 17, 1973 3 Sheets-Sheet 2 FIGZ.

AQUARIUM FILTRATION INDICATOR BACKGROUND OF THE INVENTION The presentinvention relates generally to an air operated aquarium filter, and moreparticularly to a submerged aquarium filter that is provided with anindicator to signal the amount of water flow through the filteringmedium so that the user may adjust the air flow so as to maximize waterflow. The indicator also signals the clogging of the filter medium.

Filters that may be utilized in fish tanks and aquariums or the likegenerally are provided with a housing in which is contained a filteringassembly and is arranged so that water may pass through the filteringassembly to be cleansed by the latter. Generally, the water flows intothe housing through suitably located openings in the latter and air ispumped into the housing from an external source, such as a pump or thelike, to urge or draw the water in a preferred direction through thefiltering assembly, thereafter, the water, together with the airinjected into the filtering housing, may pass out of the housing toreturn into the fish tank or aquarium. The more rapidly water movesthrough the filter, the more rapidly debris will be removed from theaquarium. The amount of water flowing through the filter varies as afunction of the amount of air flow; namely, water flow increases withincreasing air flow up to some optimum level of air flow, but if airflow is increased above this optimum level, the resulting turbulence ofair mixed with water will decrease the amount of water flow through thefilter. The optimum air flow depends both on the shape of the filterhousing and on the porosity of the filtering material. Existing 'airoperated, submerged, aquarium filters do not provide the user with meansto select an optimum level of air flow. The user commonly provides moreor less air than that required for maximum filter effectiveness.

Moreover, as those skilled in the art readily appreciate, the filteringassembly or glass wool will become clogged after extended use as itremoves debris and the like from water that passes through the housingand, thus, although the air bubbles leaving the housing may indicatethat the air pump is operating, these air bubbles may not necessarilyindicate that water is in fact passing through the clogged filteringassembly. For this reason, the housings of such filters are typicallycomprised of a transparent material so that the filtering is exposed toview. The filtering material is, furthermore, typically comprised, inpart, of some light colored material such as glass or plastic wool oropen-cell plastic foam, or the like. The darkening of this material, asit becomes laden with debris, serves as a crude indicator that thefiltering material is becoming clogged. However, as those skilled in theart readily understand, the darkening of the filter material is anunreliable indicator of filter clogging, since the debris laden, but yetunclogged, filtering material is a more effective water purificationmaterial than is a completely clean filtering material, in that thedebris laden filter material supports a variety of micro-organism, someof which trap fine particles, such as bacteria, from the water andothers of which convert noxious organic compounds dissolved in the waterinto harmless nitrogen and carbon dioxide gas. By relying on the visualappearance of the filtering medium, the user will commonly replace thefiltering material too soon or not soon enough for maximum filtereffectiveness.

The typical transparency of the filter housing, previously required topermit a convenient, if unreliable, indicator of filter functioning,imposes aesthetic problems in an aquarium. The transparent housing ismonotonous at best, and even a small quantity of debris in the filteringmaterial makes the entire assembly most unsightly. When previouslydesigned filter housings are occasionally comprised of opaque material,however, the user must generally dismantle the housing to discoverwhether or not the filtering medium is clogged. This is a cumbersomesituation, both from the standpoint of time and convenience.

Furthermore, there is an aesthetic value in visible movement of solidobjects. This is evidenced by the popularity of air activated actionornaments in aquariums, ornaments in which parts are caused to move by astream of air bubbles which strike displaceable parts of the ornamentstructure. Such ornaments serve no functional purpose in an aquariumbeyond adding a small amount of air to the aquarium water. If an actionornament provided useful information to the aquarium owner, the value ofsuch action ornamentswould be increased. Such is one function of thepresent invention.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide a filtering device that may be utilized in anaquarium or the like.

It is another object of the present invention to provide an aquariumfiltering device that includes means for indicating the operability ofthe filter.

It is still another object of the present invention to provide anair-operated filtering device including means for indicating when anoptimum amount of air is being injected into the filter.

It is still another object of the present invention to provide anaquarium filter having means for visually signalling the passage ofcontaminated water through the filtering portions thereof.

It is still another object of the present invention to provide anaquarium in which the chamber containing the filtering material may becomprised of an opaque material while providing the user withinformation concerning the clogged or unclogged nature of the filteringmedium.

It is still another object of the present invention to provide anaquarium filter that includes a decorative moving body extendingexternally of the filter, which body is driven by an impeller-carryingshaft, the latter which extends in the filter and is caused to rotateduring inflow of water in and out of the filter.

To this end, the present invention relates to a filtering devicecomprising a housing in which is provided a partition for separating thehousing into first and second chambers in communicating relation. Thehousing is provided with at least one opening through which water mayenter into the first chamber from an external water-carrying source. Thesecond chamber includes a filtering assembly for cleansing water whichhas entered the first chamber and which, thereafter, flows into thesecond chamber. An air conduit is provided for directing air into thesecond chamber for urging and drawing water through the filteringassembly. Likewise, a conduit is provided for directing both air andcleansed water out of the second chamber after the water has beencleansed by the filtering assembly. A rotary indicator is provided forsignalling visually inflow of water into the first chamber and outflowfrom the latter into the second chamber.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and additional objectsand advantages in view as will hereinafter appear, this inventioncomprises the devices, combinations and arrangements of partshereinafter described and illustrated in the accompanying drawings of apreferred embodiment in which:

FIG. 1 is a front elevational view, fragmented partially incross-section, illustrating the filtering device and indicator pursuantto the present invention as disposed at the bottom of an aquarium;

FIG. 2 illustrates a cross-sectional view taken along the line A-A inFIG. 1 of the operative association of the aquarium filter and indicatortherefor, pursuant to the present invention, in an aquarium;

FIG. 3 illustrates a perspective view of an alternate embodiment of theindicator; and

' FIG. 4 illustrates a view similar to that of FIG. 2, but showingtherelationship of the embodiment in FIG. 3 with a conventional filter.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings andmore particularly to FIGS. 1 and 2 thereof, the present inventioncomprises an aquarium filter generally denoted by the referencecharacter 10. The filter includes a housing 12 defined by a pair offront sidewalls l4 and a pair of rear sidewalls (not shown) allintegrally interconnected to one another, in a generally square-likearray, and to a bottom portion 18. The front side walls 14 are separatedfrom one another through the intermediary of a rounded vertical corner19, whereas the rear sidewalls 16 are interconnected to one another inmutually perpendicular relation (not shown). Furthermore, as illustratedin FIG. 2, the housing 12 is provided with a partition 20 which isrounded in horizontal cross-section (now shown) and acts to define twochambers 21A and 218, respectively. Chamber 21A is defined by the frontsidewalls 14 and the concavity of partition 20, whereas the chamber 218is defined by the rear sidewalls 16, together with the convexity ofpartition 20.

As illustrated most clearly in FIG. 2, the front sidewalls 14, or ineffect, the rounded corner portion 19 separating the front sidewalls 14,is provided with a plurality of vertically extending slots 22 having asomewhat parabolic vorder 23. Similarly, the bottom portion 18 of thehousing 12 is provided with a plurality of spaced slots 24. The slots 22and 24 extend generally relative to one another in mutuallyperpendicular relation.

Continuing. with reference to FIG. 2, the aquarium filter It), pursuantto the present invention, further comprises an elongate annular conduit28 which is generally tapered in cross-section and has a pair ofopposite open ends. A platform 30, having a plurality of slottedopenings 32 therein, is fixedly connected to the elongate annularconduit 28 at the lower open end thereof and extends generallytransversely thereto. The platform 30 rests on a number of spacing lugs34 (only one shown) which are provided at the bottom portion 18 of thehousing 12. The platform 30 may be fit into the housing 12 until theplatform 30 contacts the spacing lugs 34, the latter which act toprovide a clearance or define a third chamber between the platform 30and the bottom portion 18 of the housing 12, which third chambercommunicates with the conduit 28 and the second chamber 21B through theintermediary of the slotted openings 32 provided in the platform 30. Theplatform 30, internally of the chamber 218, acts to support a filteringassembly such as glass wool, charcoal and the like and, thus, the secondchamber 218 may be characterized as a filtering or cleansing chamberthrough which contaminated water may pass to be decontaminated thereby.

An air inlet conduit 36 is provided for directing air into the elongateannular conduit 28 and is connected at one end thereof to a pump (notshown in the drawings) and at the other end to an air permeable element38 which acts to disperse incoming air throughout the elongate annularconduit 28. The function of the air inlet conduit 36 and air-permeableelement 38 will be further clarified below.

The housing 12 is provided with a cover member 40 which may be press-fitonto the front and rear sidewalls embrace the latter. The cover member40 is, furthermore, provided with a raised opening 42 which surroundsthe uppermost portion of the elongate annular conduit 28 so that air andcleansed or decontaminated water may be expelled from the aquariumfilter 10. The cover member 40 is also provided with an air-vent oropening 44 at one corner thereof so that, when the aquarium filter 10 isinitially disposed into the aquarium, water may readily enter into thefilter 10 through the slotted openings 22 and 24 respectively and airexisting in the aquarium filter 10 may be readily expelled through theair vent 44 and, thus, will not present any obstacle to the inflow ofwater through the slotted openings 22 and 24 respectively.

The aquarium filter 10, as indicated above, is, provided with indicatingmeans for signalling its operability. The indicating means acts toprovide a visual signal to an observer that water is flowing into thechamber 21A through the intermediary of the slotted openings 22 and 24respectively. In this respect, the cover member 40 is provided withanother opening 46 in which is rotatably journaled freely, a rotaryshaft 48 carrying preferably helical impellers or fins 50 and extendinginternally of the chamber 21A. Extending through the opening 46,externally of the filter 10, is the upper shaft portion 52 of the shaft48 upon which is fixedly mounted a decorative spherical body 54, or thelike, upon which is provided striped markings 56, or the like, thepurpose of which will be clarified below.

In operation, the aquarium filter I0 is disposed internally of anaquarium so that water in an aquarium may readily enter into the housing12 while excess air initially in the housing 12 is expelled through theair vent 44. Water may also readily flow into the chamber 21A throughthe slotted openings 22 and 24 respectively, without obstacles thereto.The inflow of water into the chamber 21A, as indicated by the arrows inFIG. 2, will act upon the impellers 50 and due to the helical nature ofthe latter, the upflow of water from chamber 21A and down-flow from thelatter into chamber 21B will cause the rotary shaft 48 to rotate.Clearly, the spherical body 54, which is fixedly mounted upon the rotaryshaft 48, will likewise rotate together with the latter. Moreover,because of the striped markings 56, provided on the spherical body 54,the rotation of the spherical body is more visually emphasized to anobserver, such as the hobbyist who will, thereby, be signalled when thefiltering device is in fact operating. The striped spherical body couldbe replaced, asis obvious to anyone skilled in the art, by almost anyother shape such as a fish, submarine or human figure as examples, andmay, therefore, be characterized as an action ornament.

As those skilled in the art readily understand, the air tubing supplyingair to the air conduit 36 is, typically, in series with an adjustableair valve V in FIG. 4, which can be employed to increase or decrease theamount of air entering the elongated annular conduit 28. By observingthe decorative spherical body 54, while increasing and decreasing theamount of air, the user may optimize air flow by selecting that air flowwhich maximizes the rate of rotation of the spherical body 54.

Furthermore, as those skilled in the art readily understand, thefiltering material or glass wool and charcoal which are containedinternally of the chamber 21B become clogged after a period of time and,thus, upon becoming clogged, the latter obstructs the flow of water andmust be replaced to maintain the aquarium in which the aquarium filter10 is disposed in a cleansed condition. Thus, notwithstanding the factthat the pump is operating as may be indicated by the air bubbles whichascend in the elongate annular conduit 28, the filtering device 10 maybe clogged and, therefore, inoperable, which inoperability may not benecessarily easily or readily observable.

In this instance, as the filtering materials have become clogged, theoperating condition of water passing through the filtering device 10will decrease and finally terminate and clearly, the extend of waterinflow into the chamber 21A will, thereby, likewise decrease andterminate. As those skilled in the art will readily understand, atermination of water inflow into chamber 21A prevents the filteringdevice 10 from further cleansing contaminated water and is, therefore,useless unless the filtering materials as clogged are replaced.

Obviously, as the rate of water inflow into chamber 21A decreases, therate of rotation of the spherical body 54 will decrease. Once there is asufficient decrease of water inflow into chamber 21A, the impellers 50cannot respond and cause rotation of the spherical body 54. Thus, whenthe hobbyist notices that the spherical body 54 has significantlyslowed, or is not in a condition of rotation, this will indicate thatthe filtering materials require replacement because of their cloggedconditon.

Therefore, the spherical body 54 acts as an indicator for signalling theoperability and degree of operability of the filtering device 10, whenthe spherical body 54 is in a condition of rotation and relative orcomplete inoperability of the filtering device 10, or the clogged natureof the filtering materials, when the spherical body 54 slows its rate ofrotation or is not in a condition of rotation.

In the normal course of operation, water will then, after beingdecontaminated in the chamber 21B, flow into the elongate annularconduit 28 through the openings 32 provided in the platform 30 and willbe expelled from the conduit 28 at the uppermost open end of the latter.The inflow of water into the housing 12 will traverse the aforementionedpath because of the injection of air into the elongate annular conduit28 through the intermediary of the air inlet conduit 36 and theairpermeable member 38. Thus, the pressurized air which is injected intothe annular conduit 28 causes the continuous inflow of water into thehousing 12 to be cleansed by the latter and expelled therefrom togetherwith the pressurized air through the upper opening in the annularconduit 28.

Pursuant to an alternate embodiment of the invention, to permitutilization of the principal of the present invention, with aconventional filtration device denoted by the reference character 60 inFIG. 4, there is provided an insert-type of indicator denoted by thereference character 62 in FIG. 3.

The device 60 is provided with a housing 12 of generally identicalnature as that illustrated in FIGS. 1 and 2 and, thus, the samereference characters denote similar elements in both embodiments.Moreover, the device 60 is provided with a cover member 64 which ispress-fitted onto the housing 12. Although the partition 10 isillustrated in cross-section as a vertical extent which divides thehousing 12 into the chambers 21A and 213, the partition 20, inhorizontal cross-section (not shown), is preferably of arcuate extent,the purpose of which will be clarified below.

Referring now to FIG. 3 of the instant drawings, the insert-typeindicator 62 is provided with forwardly extending upper and lowerflanges 66 and 68 respectively, between which flanges is interposed in afreely journaled. fashion, a rotary shaft 70. Fixedly mounted on therotary shaft 70, for rotation therewith, are a pair of generallyhelically extending impellers 72. Moreover, the indicator 62 is providedwith a shouldered down-turned rear flange 74 which extends from avertical rear wall 76 in generally spaced relation with the latter.

The indicator 62 may be mounted upon or slipped onto the partition 20 ofthe housing 12 in a manner illustrated in FIG. 4, by removing the covermember 64 from the housing 12. Thus, because of the provision of theshouldered down-turned rear flange 74, the latter may overlie theuppermost edge portion of the partition 20 and, thereby, support theindicator 62 so as to ex tend in the chamber 21A. Moreover, theshouldered down-turned rear flange 74 and the vertical rear wall 76 areeach of arcuate extent, in horizontal crosssection (not shown), forreceiving therebetween the arcuate extent of the partition 20. Thisrelationship of the mutual arcuate extents of the flange 74, verticalrear wall 76 and partition 20 resists pivotal displacement or pivotaluplift of the indicator 62 relative to the partition 20 at the extremetop-edge of the partition 20.

The arrangement of the apparatus illustrated in FIG. 4 results in anoperation which is generally similar to the operation of the arrangementillustrated in FIGS. l and 2 and, therefore, the inflow of water intochamber 21A and the outflow of water from chamber 21A into chamber 218causes the helical impellers 72 to rotate relative to the flanges 66 and68 respectively, which rotation may be readily observed externally ofthe housing 12, since the housing 12 is commonly constituted oftransparent material. Moreover, in order to enhance the extent ofobservation of the rotation of the impellers 72, the latter may beprovided with opaque strips or other suitable markings (not shown) in amanner illustrated in FIG. 2 for the spherical body 54, for emphasizingthe fact that the rotary shaft is in a condition of rotation and thatthe filtration device is in a condition of operation, in a manneraforementioned for the embodiment illustrated in FIGS. 1 and 2.

Both embodiments of the invention illustrated in FIGS. 1, 2, 3 and 4,can conceal the unsightly, debris laden filter material from viewwithout interfering with the utility of the filter. In the embodimentshown in FIGS. 1 and 2, the entire housing 12, and cover 40, can becomprised of an opaque material because the movement, or lack ofmovement, of the spherical body 56 informs the user of the condition ofthe filtering material. In the embodiment illustrated in FIGS. 3 and 4,all of the housing can be opaque except for the outer walls of chamber21A, in which the impellers 72 are located.

Numerous alterations of the structure herein disclosed will suggestthemselves to those skilled in the art. However, it is to be understoodthat the present disclosure relates to a preferred embodiment of theinvention which is for purposes of illustration only and is not to beconstrued as a limitation of the invention. What is claimed is:

1. An aquarium filtering device in combination with an aquarium tankhaving contaminated and decontaminated water therein, said filteringdevice comprising in combination a housing provided with three chambersdefining a first inlet chamber in fluid flow relation with the aquariumtank and a second filtration chamber in fluid flow relation with saidfirst'inlet chamber and a third outlet chamber in fluid flow relationwith said second filtration chamber, a mass of filtering material insaid second filtration chamber, said third outlet chamher being providedwith opening means for ingress of air into said third outlet chamber andegress of decontaminated water out of said third outlet chamber into.the aquarium tank, said first inlet chamber being provided with inletmeans comprising an inlet through which contaminated waterfrom the tankmay flow, an air stream supply means disposed in said third outletchamber which directs ingressed air from said opening means into saidthird outlet chamber thereby when the filtering material is uncloggedcausing contaminated water from the aquarium tank to flow through saidinlet into said first inlet chamber and therefrom into said secondfiltration chamber where the contaminated water is substantiallydecontaminated by the filtering material before flowing into said thirdoutlet chamber and being egressed through said opening means into theaquarium tank, and indicating means associated with said first inletchamber and responsive to flow of water from said inlet to said secondfiltration chamber for signalling flow of the contaminated water throughthe filtering material, said indicating means including a rotary shaftsupported in said first inlet chamber, said shaft being provided with atleast one helical impeller for indicating rate of flow of the water fromsaid inlet to said second filtration chamber.

2. A filtering device as claimed in claim 1 including means forcontrolling the amount of air directed into said third outlet chamberand, thereby, controlling the rate of movement of said indicating means.

3. A filtering device as claimed in claim 1, wherein said shaft isrotatively connected to a cover portion of said housing.

4. A filtering device as claimed in claim 1 wherein a portion of saidhousing is constituted of opaque material for concealing said filteringmeans.

5. A filtering device as claimed'in claim 1 wherein said indicatingmeans includes a body disposed externally of said housing andoperatively associated with said shaft for movement when said shaftundergoes rotation.

6. A filtering device as claimed in claim 1 wherein said indicatingmeans includes a body disposed externally of said housing and fixedlysupported on said shaft for rotation together with said shaft.

7. A filtering device as claimed in claim 6 wherein said body includesmarkings which undergo rotation therewith for emphasizing rotation ofsaid body.

8. A filtering device as claimed in claim 1 including securing meansdisposed within said housing for detachably connecting said indicatingmeans to said filtering device.

9. A filtering device as claimed in claim 8 wherein said securing meansand said filtering device include interfitting members which areoperatively associated with one another in detachable slip-on relation.

10. A filtering device as claimed in claim 9, wherein said securingmeans includes a down-turned flange portion for overlying and restingfreely on an upper portion of a vertically extending partition memberdisposed in said housing, said partition member separating said firstinlet chamber from said second filtration chamber.

11. A filtering device as claimed in claim 9 wherein said securing meansincludes a down-turned flange portion for overlying and resting freelyon an associated interfitting member of said filtering device.

12. A filtering device as claimed in claim 11 wherein said interfittingmembers include arcuate extents respectively engageable with one anothertransversely of the down-turned extent of said flange portion.

1. An aquarium filtering device in combination with an aquarium tankhaving contaminated and decontaminated water therein, said filteringdevice comprising in combination a housing provided with three chambersdefining a first inlet chamber in fluid flow relation with the aquariumtank and a second filtration chamber in fluid flow relation with saidfirst inlet chamber and a third outlet chamber in fluid flow relationwith said second filtration chamber, a mass of filtering material insaid second filtration chamber, said third outlet chamber being providedwith opening means for ingress of air into said third outlet chamber andegress of decontaminated water out of said third outlet chamber into theaquarium tank, said first inlet chamber being provided with inlet meanscomprising an inlet through which contaminated water from the tank mayflow, an air stream supply means disposed in said third outlet chamberwhich directs ingressed air from said opening means into said thirdoutlet chamber thereby when the filtering material is unclogged causingcontaminated water from the aquarium tank to flow through said inletinto said first inlet chamber and therefrom into said second filtrationchamber where the contaminated water is substantially decontaminated bythe filtering material before flowing into said third outlet chamber andbeing egressed through said opening means into the aquarium tank, andindicating means associated with said first inlet chamber and responsiveto flow of water from said inlet to said second filtration chamber forsignalling flow of the contaminated water through the filteringmaterial, said indicating means including a rotary shaft supported insaid first inlet chamber, said shaft being provided with at least onehelical impeller for indicating rate of flow of the water from saidinlet to said second filtration chamber.
 2. A filtering device asclaimed in claim 1 including means for controlling the amount of airdirected into said third outlet chamber and, thereby, controlling therate of movement of said indicating means.
 3. A filtering device asclaimed in claim 1, wherein said shaft is rotatively connected to acover portion of said housing.
 4. A filtering device as claimed in claim1 wherein a portion of said housing is constituted of opaque materialfor concealing said filtering means.
 5. A filtering device as claimed inclaim 1 wherein said indicating means includes a body disposedexternally of said housing and operatively associated with said shaftfor movement when said shaft undergoes rotation.
 6. A filtering deviceas claimed in claim 1 wherein said indicating means includes a bodydisposed externally of said housing and fixedly supported on said shaftfor rotation together with said shaft.
 7. A filtering device as claimedin claim 6 wherein said body includes markings which undergo rotationtherewith for emphasizing rotation of said body.
 8. A filtering deviceas claimed in claim 1 including securing means disposed within saidhousing for detachably connecting said indicating means to saidfiltering device.
 9. A filtering device as claimed in claim 8 whereinsaid securing means and said filtering device include interfittingmembers which are operatively associated with one another in detachableslip-on relation.
 10. A filtering device as claimed in claim 9, whereinsaid securing means includes a down-turned flange portion for overlyingand resting freely on an upper portion of a vertically extendingpartition member disposed in said housing, said partition memberseparating said first inlet chamber from said second filtration chamber.11. A filtering device as claimed in claim 9 wherein said securing meansincludes a down-turned flange portion for overlying and resting freelyon an associated interfitting member of said filtering device.
 12. Afiltering device as claimed in claim 11 wherein said interfittingmembers include arcuate extents respectively engageable with one anothertransversely of the down-turned extent of said flange portion.